What is the name of the process in which coal is heated in absence of air?
The process is called destructive distillation of coal.
What is coke?
The greyish-black residue left after destructive distillation of coal is called coke.It is a tough, porous and black substance. It is almost pure form of carbon.
Which variety of coal contains maximum amount of carbon?
Anthracite contain maximum amount of carbon.